Egg carton with collapsible bubbles

Abstract

A plastic egg carton that enables secure packaging of different size eggs, preferably in both oriented and non-oriented positions, while also allowing for easy filling, closing, handling and packing in shipping containers. The egg carton has a base tray and a lid hingedly connected to the tray for pivoting between open and closed positions. Each cell of the base tray has a plurality of collapsible bubbles formed in the cell sidewall, the bubbles extending radially inwardly in a relaxed state (when no egg or an egg up to a predetermined size (diameter) is present in the cell) and configured to move (compress) outwardly when eggs of increasing size (diameter) above the predetermined size are placed in the cell, thereby accommodating a range of different size variations, and holding each received egg in a vertically aligned position in its cell. The lid post also has a plurality of collapsible bubbles. The bubbles in the cell sidewalls and lid posts collectively hold each egg, within a predefined range of egg sizes, vertically upright in the cell pocket, resisting movement in the horizontal (lateral) direction, and cushioning the egg at its point of maximum girth (maximum width) from compressive forces (lateral impacts).

1 . A plastic egg carton comprising:
 a tray and a lid hingedly connected to the tray for pivoting between open and closed positions, the tray and the lid having respective peripheral edges that mate with each other in the closed position, the egg carton having in the closed position a length and a width in a horizontal plane, and a height in a vertical direction transverse to the horizontal plane;   the tray having a cell matrix comprising a plurality of equal size cells for receiving individual eggs, the cells being arranged successively adjacent one another along the length and width of the carton and each cell having a central vertical axis aligned with the height of the carton and extending upwardly toward the lid;   each cell having a bottom wall and a sidewall extending upwardly from the bottom wall to form a corresponding one of the cells, and the tray having a plurality of cell posts, each cell post being formed at an intersection of four adjacent cells as an extension of the sidewalls of the four adjacent cells, and each cell post having a central vertical axis aligned with the height of the carton and extending upwardly toward the lid;   the lid having a plurality of lid posts, each lid post being co-axially aligned with the axis of a respective cell post and extending downwardly toward the tray with a mating surface for engaging with the respective cell post when the lid is in the closed position;   the tray and lid having a plurality of collapsible bubbles, disposed on the cell sidewalls and the lid posts, that are each movable from an innermost relaxed state configured to engage a smaller size egg within a range of different size variations, outwardly to a plurality of compressed states, to engage an ovoid surface area of an egg disposed in the respective cell so as to deter movement and hold in vertical alignment with the central vertical cell axis any size egg within the range of different size variations,   wherein the collapsible bubbles are configured to collapse progressively radially outwardly away from the central vertical cell axis as eggs of increasing size within the range are introduced into the cell.   
     
     
         2 . The egg carton of  claim 1  wherein each cell sidewall has a contoured interior surface configured to engage an ovoid shape of an egg, and a plurality of the collapsible bubbles are disposed on the contoured interior surface and extend radially inwardly from the contoured interior surface toward the central vertical cell axis in the relaxed state. 
     
     
         3 . The egg carton of  claim 2  wherein each lid post has a plurality of partial ovoid shaped depressions for engaging the ovoid shape of eggs received in the adjacent cells, and at least one of the collapsible bubbles is disposed on each depression and extends radially inwardly toward the respective central vertical cell axis in the relaxed state. 
     
     
         4 . The egg carton of  claim 3  wherein each lid post has four of the partial ovoid depressions, one for engaging with eggs received within each of the four adjacent cells when the lid is in the closed position. 
     
     
         5 . The egg carton of  claim 1  wherein each cell post has an uppermost surface for engaging with a mating surface of the respective lid post when the lid is in the closed position. 
     
     
         6 . The egg carton of  claim 1  wherein the lid includes a connecting wall between each pair of adjacent lid posts. 
     
     
         7 . The egg carton of  claim 1 , wherein the collapsible bubbles have a wall thickness that is less than a wall thickness of the cell sidewalls. 
     
     
         8 . The egg carton of  claim 7  wherein the collapsible bubbles have a wall thickness of at least 35% less that the wall thickness of the cell sidewalls, more preferably in a range of 40 to 60% less, and still more preferably in a range of 45 to 50% less. 
     
     
         9 . The egg carton of  claim 1  wherein the cell sidewalls have a wall thickness in a range of 35 to 75 mils, and the collapsible bubbles have a wall thickness in a range of 20 to 45 mils. 
     
     
         10 . The egg carton of  claim 1  wherein the range of different size variations is from 50 to 78 ounces per egg, with the egg disposed in either an oriented or a non-oriented direction in the cell. 
     
     
         11 . The egg carton of  claim 1  wherein the range of different size variations is from 65 to 78 ounces per egg, with the egg disposed in either an oriented or a non-oriented direction in the cell. 
     
     
         12 . The egg carton of  claim 1  wherein the range of different size variations is from 50 to 65 ounces per egg, with the egg disposed in either an oriented or a non-oriented direction in the cell. 
     
     
         13 . The egg carton of  claim 1  wherein the plastic is a foam or non-foam plastic material. 
     
     
         14 . The egg carton of  claim 1  wherein the plastic is a foam plastic material. 
     
     
         15 . The egg carton of  claim 1  wherein the plastic is styrene foam material. 
     
     
         16 . The egg carton of  claim 1 , wherein the plastic is one or more of polyester, polyethylene, polylatic acid, and polystyrene, including polymers, copolymers, mixtures and blends thereof. 
     
     
         17 . The egg carton of  claim 1 , wherein the carton comprises a non-foam polyester. 
     
     
         18 . The egg carton of  claim 1 , wherein the carton comprises an integral foamed sheet of polystyrene material. 
     
     
         19 . The egg carton of  claim 18 , wherein the cell sidewalls have a thickness in a range of 35 to 75 mils. 
     
     
         20 . The egg carton of  claim 1 , wherein the tray has a 2×6 matrix of the cells. 
     
     
         21 . The egg carton of  claim 1 , wherein the tray has a 2×3, 2×4, 2×5, 2×6, 3×3, 3×4, 3×5, 3×6, 4×4, 4×5, 4×6, 5×5, 5×6 or 6×6 matrix of the cells. 
     
     
         22 . The egg carton of  claim 1 , wherein each cell has an arcuate, outwardly bowed sidewall portion sized to receive a major cell diameter of a jumbo egg in a range of about 1.75 to about 2.06 inches, and the distance between the cell bottom wall and the lid is configured to hold a jumbo egg in a height range of 2.461 to 2.750 inches. 
     
     
         23 . The egg carton of  claim 1 , wherein the sidewalls of two adjacent cells form a cell divider which prevents contact between eggs in the adjacent cells. 
     
     
         24 . The egg carton of  claim 1 , wherein the carton in the closed position has a length of from about 11.62 to about 12.00 inches, a width of from about 3.95 to about 4.00 inches and a height of from about 2.62 to about 3.125 inches. 
     
     
         25 . The egg carton of  claim 1 , wherein the cell bottom walls are movable to accommodate eggs of various sizes in the range. 
     
     
         26 . The egg carton of  claim 25 , wherein the movable cell bottom walls and collapsible bubbles accommodate eggs that are disposed in either an oriented or a non-oriented direction in the cells. 
     
     
         27 . The egg carton of  claim 1 , wherein the carton is filled with eggs of varying sizes in the range. 
     
     
         28 . A stack comprising a plurality of filled egg cartons of  claim 27  arranged in a vertical stack. 
     
     
         29 . A container holding the vertical stack of filled egg cartons of  claim 28 . 
     
     
         30 . A container holding a full case or half case of the filled egg cartons of  claim 27 . 
     
     
         31 . A method of assembling a stack of the egg cartons of  claim 1 , including for each of a plurality of the egg cartons of  claim 1 , filling the cells of the egg carton with eggs of varying sizes in the range, closing the lid over the base, and stacking a plurality of the filled egg cartons in a vertical stack.